Hypersonic cooling device



Ap 1964 LIAN-TONG WEN HYPERSONIC COOLING DEVICE Filed Aug. 29, 1960I!Illllfllllllllfl/llrllll llI' ll United States Patent 3,129,667HYPERSGNIC CGOLING DEVICE Lian-Tong Wen, 601 W. 112th St, New York 25,N.Y. Filed Aug. 29, 19%, Ser. No. 52,490 2 Claims. (Cl. 10292.5)

The present invention relates to a cooling device for air vehicles and,more particularly, for hypersonic air Vehicles such as missiles,aircraft and space vehicles.

The invention provides for a novel air cooling device, for the nose orleading portions of air vehicles, having no moving parts and affordingfully automatic refrigeration with instantaneous reaction. The device issimple to construct and operate, lightweight and economical tomanufacture.

The air cooling device is particularly effective for cooling the nosecones of missiles and the leading edges of hypersonic aircraft thatattain high temperatures during flight.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combinations of elements, and arrangement of parts, which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a cross sectional view of a nose cone of a missileillustrating the cooling device; and

FIG. 2 is a cross sectional view of a nose cone of a missileillustrating a modification of the cooling device.

Referring to the drawings in which like numerals identify similar partsthroughout, FIG. 1 illustrates a preferred embodiment of the coolingdevice. Missile 1 has a leading portion or nose cone 2 having arearwardly extending outer surface. An outer shell or outer cone 3 has arearwardly extending inner surface extending over said nose cone 2substantially conforming to the contour of nose cone 2. The innersurface area of outer shell 3 is larger than the outer surface area ofnose cone 2. There are attachment means 6 which may be suitablemechanical attachment means that fix or connect shell 3 to nose cone 2and spatially separate the outer surface of nose cone 2 from the innersurface of shell 3 to provide a rearwardly extending channel or conduitbetween the shell and nose cone that opens or exhausts to the atmosphereat port 7 positioned rearwardly of nose cone 2. Positioned in theleading or forward portion of shell 3 are a plurality of orifices 4,communicating air in front of the shell with a forward portion of saidconduit. The orifices which are adapted to permit flow of air from theouter surface of the forward portion of the shell to the conduit are ofsmall cross sectional area relative to the cross sectional area of theforward portion of conduit 5 at the forward portion of shell 3 and nosecone 2. There may also be at least one such orifice 4 positioned in theforward portion of shell 3, instead of a plurality of such orifices asillustrated in FIG. 1.

Dashed line A represents the diameter of outer shell 3 and dashed line Brepresents the diameter of nose cone 2. When A, the diameter of outershell 3, is larger than B, the diameter of nose cone 2, more efficientexpansion of air and speed of exhaust may be attained.

FIG. 2 illustrates a modification of the cooling device illustrated inFIG. 1 and has a single orifice 4. The arrows indicate the direction offlow of ram air. In combination with the device illustrated in FIG. 2there is a generally conical deflector 21 attached to the forwardportion of nose cone 2 and positioned in the forward portion of con-3,129,667 Patented Apr. 21, 1964 ice duit 5. Deflector 21 is disposedwith its apex positioned toward the outer shell 3 in the forward portionof the conduit. The deflector 21 may also be attached by suitablemechanical means to the forward portion of the inner surface of outershell 3.

The efiiciency of the cooling device may be further improved byincreasing the rate of heat radiation of the heated compressed ram airby providing, in combination with the shell and nose cone, a heatradiating material or glow booster 8 on the forward portion of shell 3that becomes highly incandescent when heated by the in-rushingcompressed ram air and that radiates heat away from the shell to coolsuch portion. The heat radiating material may also be affixed to theforward portion of the nose cone. The heat radiating material or glowbooster 8 may be made of material that becomes incandescent and highlyreflective when heated, as for example, zirconia (ZrO zircon (ZrSiOthori-a (ThO lime (CaO), and the like. It is preferred that one or moreof these substances be included in substantial amount to take advantageof their high radiation by incandescence at relatively low temperatures.The glow booster may be aflixed to the outer surface of the forwardportion of the shell by flame spraying, or by mechanical attachment orby any other suitable means. The shell or the nose cone, or both, mayincorporate a substantial amount of such heat radiating material or evenbe constructed principally thereof.

The materials used in the construction of the cooling device may be theconventional heat resistant materials such as metal, ceramics, and thelike that are employed in high speed air vehicles, missiles and thelike.

The term forward portion of the conduit or channel as used herein meansthat portion of the conduit or channel that is intersected by a planeperpendicular to the central axis of the nose immediately forward of thepoint of the nose, the central axis being that longitudinal axis normalto the surface at the point of the nose or leading edge. The forwardportion and the plane describing it are indicated at 1010 in FIG. 2.

From the foregoing description it will be obvous to one skilled in theart that the cooling device may be adapted for the leading edges ofWings and the like parts of aircraft and space vehicles. The orifice mayalso bein the form of a slot or a series of slots.

In practice the cooling device operates in the following manner. Whenmissile 1 or a wing section constructed to utilize my invention ramsthrough the air at hypersonic speed, air at the nose of the missile orwing is compressed and heat is developed. Some of the heat transfers tothe forward portion of outer shell 3 and some of the heat radiates intothe atmosphere in the form of light. This dissipates some of the heatthat developed from compression of A portion of the hot compressed ramair enters orifice 4 which is of relatively small cross sectional areain relation to the cross sectional area of the forward portion ofconduit 5. Upon entering the larger area of the forward portion ofconduit 5 the heated compressed ram air expands and is thereby cooled.As the cooler expanded air passes rearwardly through conduit 5 andexhausts into the atmosphere at port 7 it absorbs heat from the outersurface of nose cone 2 and from the inner surface of outer shell 3, sothat those surfaces heated by the compressed ram air are cooled, and thetemperature of those surfaces is suflicienltly reduced to avoid acritical harmful temperature. Thus, a means of avoiding destructiveoxidation or burning of the nose cone is presented.

The rate and extent of cooling is dependent on the pressure differentialbetween the forward portion of conduit 5 and the ram air on the exteriorof the leading portion or nose of the shell 3 which in turn is dependenton the ratio of the cross sectional area of the forward portion of theconduit to the cross sectional area of the orifice or orifices. It ispreferred that this ratio be at least :1. Effective cooling may also beenhanced by deflecting the cooled expanded air against the outer shellas shown in FIG. 2.

To facilitate exhaust without unduly alfecting ballistic properties itis preferred that the cross sectional area of the conduit at the pointof exhaust be less than the cross sectional area of the forward portionof the conduit but that the cross sectional area at the point of exhaustbe not less than about 10 times the cross sectional area of the orificeor orifices.

The cooling device is continuous in its action and starts automaticallyas the outer shell and nose cone begin to generate heat due tocompression of air and the capacity of the device increases as thetemperaure rises from increased pressures. The instantaneous reaction ofthe cooling device to pressure changes makes it especially suitable forhypersonic air vehicles. Furthermore, no moving parts or complicatedstructure are necessary.

The modification of the cooling device illustrated in FIG. 2 operates insubstantially the same manner as the device illustrated in FIG. 1. Theemployment of a highly reflective heat radiating material or glowbooster on the outer surface of the forward portion of the outer shellradiates away some of the heat from the outer surface and furtherimproves the cooling results. When the missile rams through the air athypersonic speed and compressed air develops heat at the forward portionof the shell the intensity of glow from the highly reflective andincandescent heat radiating material increases and some of the heat isradiated away from the outer surface of the outer shell. The employmentof the heat radiating material or glow booster in combination with thecooling device of the present invention achieves cooling of the heatednose or leading portion by radiation and by heat transfer andabsorption.

The employment of the deflector in combination with the nose cone andouter shell deflects the cooled expanded air against outer shell 3 anddeflects in-rushing heated compressed ram air away from the forwardportion of nose 2 and such portion is maintained at a cooler temperaturethan when the path of heated compressed air hits it directly.

FIGURE 1 also shows another embodiment of the principle of my invention.In this embodiment the nose or leading portion of an air vehicle havinga rearwardly extending outer surface may have an orifice 31 or orificespositioned in its forward extremity communicating air in front of thenose or leading portion with a rearwardly extending conduit 32positioned in the interior of the nose or leading portion of thevehicle. The conduit has at least One exhaust opening 33 communicatingwith interior portions of the vehicle and with the atmosphere at 34rearwardlyofthe leading portion. In this embodiment, the air isexpandedin the conduit, and the cooled air passes through a conduit orconduits and serves to cool the in terior portions, mechanisms and thelike, of the vehicle.

It will thus be seen that the objects set forth above among those madeapparent from the preceding description, are efiiciently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the features of the invention herein described, and allstatements of the scope of the invention which might be said to falltherein.

This application is a continuation-in-part of application Serial No.774,275, filed November 17, 1958, now abandoned.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. An air cooling device for the interior portion of an air vehiclewhich comprises in combination, a leading portion having a rearwardlyextending outer surface, a rearwardly extending conduit positioned inthe interior of said leading portion, said leading portion having atleast one orifice positioned in the forward extremity of said leadingportion communicating air in front of the leading portion to saidconduit, said conduit having an exhaust opening communicating with theinterior portion of the air vehicle and with the atmosphere rearwardlyof said leading portion.

2. An air cooling device for the interior portion of an air vehiclewhich comprises in combination a leading portion having a rearwardlyextending outer surface, a heat radiating material affixed to the outersurface of the leading portion, said heat radiating material comprisingmaterials selected from the group consisting of zirconia, zircon, thoriaand lime, a rearwardly extending conduit positioned in the interior ofsaid leading portion, at least one orifice positioned in the forwardextremity of said leading portion communicating air in front of theleading portion to said conduit, said conduit communicating with theinterior portion of the air vehicle and being open to the atmosphere ata point of exhaust rearward of the leading portion.

References Cited in the file of this patent UNITED STATES PATENTS1,510,955 Paisley Oct. 7, 1924 2,678,887 Hathaway May 18, 1954 2,767,463Tacvorian Oct. 23, 1956 2,922,291 Fox et al Jan. 26, 1960 2,926,612 OlinMar. 1, 1960 FOREIGN PATENTS 411,485 Italy Aug. 9, 1945 OTHER REFERENCESHuppert: New Aspects in Ceramic Coatings, American Rocket SocietyJournal, January 1959, pages 19-21.

1. AN AIR COOLING DEVICE FOR THE INTERIOR PORTION OF AN AIR VEHICLEWHICH COMPRISES IN COMBINATION, A LEADING PORTION HAVING A REARWARDLYEXTENDING OUTER SURFACE, A REARWARDLY EXTENDING CONDUIT POSITIONED INTHE INTERIOR OF SAID LEADING PORTION, SAID LEADING PORTION HAVING ATLEAST ONE ORIFICE POSITIONED IN THE FORWARD EXTREMITY OF SAID LEADINGPORTION COMMUNICATING AIR IN FRONT OF THE LEADING PORTION TO SAIDCONDUIT, SAID CONDUIT HAVING AN EXHAUST OPENING COMMUNICATING WITH THEINTERIOR PORTION OF THE AIR VEHICLE AND WITH THE ATMOSPHERE REARWARDLYOF SAID LEADING PORTION.